Die casting machine



ma e. 15, 1942' V. H. DUPRE DIE CASTING MACHINE Filed Jan. 10, 1941 ZSheets-Sheetl lav/rm, V

Fatentecl Dec. 15, W42

UNITED STATES PATENT OFFICE DIE CASTING MACHINE Application January 10, 1941, Serial No. 373,967

9 Claims.

This invention relates to die casting machines, and more particularly to a casting ejector mechanism for die casting machines.

In conventional die casting machines, the castings are usually ejected from the die cavities by means of ejector pins which are projected into the die cavity to dislodge the casting therefrom. Although this method of ejecting the castings is generally satisfactory, difllculties are sometimes encountered due to the tendency of some castings to' stick to the ejector pins after being dislodged from the die cavity. This condition is very objectionable, particularly in automatic machines, since it necessitates the stopping of the machine in order to remove such castings.

Objects of the present invention are to eliminate the above mentioned objections by providing simple and inexpensive mechanism for ejecting the castings from the ejector pins.

One embodiment of the invention contemplates the provision of a die casting ejector mechanism in which the casting is dislodged from the die cavity by means of the usual ejector pins, and an auxiliary ejector member then operates automatically to positively eject the casting from the ejector pins.

The invention is illustrated in the accompanying drawings, in which,

Fig 1 is a, fragmentary vertical sectional view of a die casting die and ejector mechanism embodying the invention, the die being shown in its closed position;

Fig. 2 is a similar sectional view with the die shown in its open position;

Fig. 3 is a fragmentary vertical sectional view similar to Fig. 1, showing an alternative form of ejector mechanism, the die being shown in its closed position, and

Fig. 4 is a similar sectional view with the die shown in its open position.

Referring to the drawings, the die casting die illustrated therein comprises a stationary member Ill and a movable member cooperating therewith to provide a die cavity 2 for casting an article l3. The movable die member is at tached to a reciprocatory die carrier (not shown) and has associated therewith an ejector plate l5, which is mounted for movement with respect to the movable die member. Attached to the ejector plate are two ejector pins H and I8 which are slidable in the movable d e member and are adapted to engage the cast article. Ejector pin I8 may be arranged as illustrated so that a portion thereof is adapted to engage the face of stationary die member II]. when the die is closedv and thereby automatically reset the ejector plate to the casting position, wherein the end surfaces of the ejector pins are flush with the wall of the die cavity. However, one or more separate or additional reset pins, such as illustrated and designated by the numeral 20, are usually employed for resetting the ejector plate.

In the embodiment of the invention illustrated in Figs. 1 and 2, an auxiliary ejector pin 2| is provided for ejecting the casting from the main ejector pins l1 and I8 after the casting has been ejected from the die cavity This auxiliary ejector pin is slidable in the movable die member H and is adapted to engage the cast article, as shown in Fig. 1. It is actuated by a lever 23 pivotally suspended on a pin 24 in a slot 25 provided in the movable die member. The lever, in turn, is actuated by a pin 21 attached to ejector plate l5. When the die is closed, the end of pin 21 is spaced apart from the lever 23, as shown in Fig. 1, the space therebetween being suificient to permit ejection of the cast article from the die cavity by the main ejector pins l1 and I8 before the auxiliary ejector pin 2| is actuated to separate or eject the cast article from the ends of the main ejector pins. The operation of this embodiment of the invention is as follows:

When the die is closed, the main ejector pins ll and I8 are properly set for casting through the engagement of reset pin 20 and ejector pin it with the fact of stationary die member Hi. The auxiliary ejector pin 2| is also properly set through the engagement of a portion thereof with the face of the stationary die member, as shown in Fig. 1. After each casting operation, the die is opened by moving the movable die member away from the stationary die member. The cast article remains in the movable die member and, therefore, the ejector plate l5 moves with the movable die member until its movement is interrupted by suitable stops 30-30, after which further movement of the movable die member causes the main ejector pins l1 and I8 to be projected through the movable die member, thereby dislodging the cast article from the die cavity. During the final portion of the opening movement of the movable die member, the lever 23 is engaged and actuated by the pin 21, whereby the auxiliary ejector pin 2| is projected through the movable die member, as illustrated in Fig. 2. thus positively separating the cast article from the ends of the main ejector pins. It will be noted that the cast article is first dislodged from the die cavity by the main ejector pins and then separated from the latter by the auxiliary ejector pin, which is projected forwardly by the lever'23 to a position in advance of the main ejectorpins. The cast article is thus pushed or knocked off of the main ejector pins.

In the embodiment of the invention illustrated in Figs. 3 and 4, an auxiliary ejector pin 35 is provided for separating or ejecting the cast article from the ends of the main ejector pins ii and id. This auxiliary ejector pin is slidable in movable die member II and its forward end surface is engageable partially with the cast article and partially with the face of stationary die member is, as shown in Fig. 3. The rear end of the auxiliary ejector pin is slidable in ejector plate iii and is adapted to be engaged by an air operated plunger 38 attached to a piston 39 operating in a cylinder li) carried by the ejector plate. Compressed air is supplied to the cylinder under the control of a valve 42 which is connected to the cylinder by a conduit 43 and is operated by an arm or bracket 36 attached to movable die member ii. The valve normally connects the rear end of air cylinder 40 with an exhaust line 35; and the piston 39 and plunger 38 are normally urged toward the rear end of the cylinder by a compression spring Q7, as shown in Fig. 3. When actuated by the bracket M, the air valve connects the rear end of the cylinder to a compressed air line 38, whereupon the plunger 38 is pressed forwardly against the rear end of the auxiliary ejector pin. The operation of. this embodiment of the invention is as follows:

When the die is closed, the main ejector pins ii and i8 are properly set for casting through the engagement of reset pin 20 and ejector pin i8 with the race of stationary die member JO.

The auxiliary ejector pin 35 is also properly set through its engagement with the face of the stationary die member, as shown in Fig. 3. An annular flange Q9 is provided near the rear end J of the auxiliary ejector pin for limiting its rearward movement by engaging the front of the auxiliary ejector pin. The latter is therewhich jars the cast article free from the ends of the main ejector pins.

Upon movement of the movable die member to its closed position, the air valve- 42 is spring returned to its normal position, whereupon the plunger 38 is retracted to its normal position by the spring 67. The auxiliary ejector pin and the main ejector pins are automatically reset upon closing of the die as explained above.

It should be understood that the invention is asoacoo not limited to the particular embodiments thereof herein illustrated and described, except insofar as is defined by the appended clai rns.

What is claimed is:

1. In a die casting machine, a die comprising complementary members cooperating to provide a casting cavity, one of said members being movable relative to the other to permit the removal of a cast article from said cavity, a main ejector pin slidably carried by said movable die member and rendered efiective by a movement of said die member away from the other die member for ejecting a cast article from the die cavity, an auxiliary ejector pin for thereafter separating the article from the main ejectorpin, and means rendered efiective by said movement of the movable die member for actuating the auxiliary ejector pin.

2. In a die casting machine, a die comprising complementary members cooperating to provide a casting cavity, one of said members being movable relative to the other to permit the removal of a cast article from said cavity, ejector means for dislodging the cast article from said cavity, and means rendered effective by a movement of said movable die member away from the other die member for separating the article from said ejector means.

3. In a die casting machine, a die comprising complementary members cooperating to provide a casting cavity, one of said members being movable relative to the other to permit the removal of a cast article from said cavity, ejector means rendered efifective by a movement of the movable die member for dislodging the cast article from said cavity, and means rendered efiective by further movement of said die member in the same direction for separating the article from said ejector means.

4. In a die casting machine, a die comprising complementary members cooperating to provide a casting cavity, one of said members being movable relative to the other to permit the removal of a cast article from said cavity, means tor ejecting the article from said cavity, a member slidable in one of said die members for separating the article from said ejecting means, a lever for actuating said slidable member, and means rendered effective by a movement of the movable die member for actuating said lever.

5. In a die casting machine, complementary die members cooperating to provide a casting cavity, one of said members being movable relative to the other to permit the removal of a cast article from said cavity, means for ejecting the article from said cavity, a pin slidable in the movable die member for separating the article from said ejecting means, a lever carried by the movable die member for actuating the slidable pin, and means rendered effective by a predetermined movement of the movable die member away from the other die member for actuating said lever.

6. For dislodging a finished casting from a die casting machine, a pair of projectible members ending flush with the die cavity in retracted position and cooperating to eject the casting from the mold and means to impart differential relative movement to said members to tilt the caste ing-and thereby simultaneously break its bonds on the ends of both members.

7. In a die casting machine, the combination with a die having a die cavity, of a pair of projectible members terminating in the die cavity for cooperating to eject a finished casting from I said die cavity, and means to impart differential relative movement to said members to separate the casting from both members simultaneously.

8. In a die casting machine, the combination with a die comprising complementary members cooperating to provide a casting cavity, one of said members being movable relative to the other to permit the removal of a finished casting from said cavity, of means for dislodging a finished casting from said cavity, said means comprising a pair of projectible members slidable in one of the die members for clislodging the casting from the die cavity, and means for moving one of the projectible members with respect to the other to separate the casting from both members simultaneously.

9. In a die casting maehi e, the combination with a die comprising complementary members cooperating to provide a casting" cavity. one of said member being movable relative to the other to permit the removal of a finished casting iroin said cavity, of means for dislodging a finished casting from said cavity, said means comprising a pair of projectible member slidable in the movable die member in response to a movement of said die member, whereby the casting is dislodged from said die member, and means responsive to a further movement of said die member for moving one of the projectible members with respect to the other to separate the casting from both members simultaneously.

VALENTINE H. DUPRE'. 

